Evidence for strong Coulomb correlations in the metallic phase of vanadium dioxide

The influence of Coulomb correlations on magnetic and spectral properties in the metallic rutile phase of vanadium dioxide is studied by state of the art LDA + DMFT method. Calculation results in strongly correlated metallic state with an effective mass renormalization m*/m ≈ 2. Uniform magnetic susceptibility shows Curie-Weiss temperature dependence with effective magnetic moment, p _eff^theor = 1.54μ_B, in a good agreement with the experimental value p _eff^exp = 1.53μ_B that is close to ideal value for V⁴⁺ ion with the spin S = 1/2, p _eff = 1.73μ_B. Calculated spectral function shows well developed Hubbard bands observable in the recent experimental photoemission spectra. We conclude that VO₂ in rutile phase is strongly correlated metal with local magnetic moments formed by vanadium d-electrons.